The present invention relates to a new and distinct cultivar of Phlox paniculata plant, known as Phlox paniculata ‘Shockwave’ and will be referred to hereafter by its cultivar name, ‘Shockwave’, or the “new plant”. The new plant was discovered in spring of 2008 and separated out for further evaluation in the summer of 2008 by Lonette A. Lemberger from a tissue-cultured batch greenhouse grown plantlets at a nursery in Zeeland, Mich., USA. The single whole plant mutation originated as an uninduced sport from Phlox ‘David's Lavender’ (not patented). The plant has been asexually propagated by stem cuttings at the same nursery in the greenhouses in Zeeland, Mich. The unique characteristics of the new plant have been found to be reproducible and stable in successive generations of asexually propagated and the resultant plants have been found to be identical to the original selection.